Strap for Seamaster 120M Automatic 36.25 Yellow Gold / Champagne

The exact lug width is 18 millimeters. This measurement, also known as lug width, is the distance measured between the two watch lugs (metal attachment points) and determines compatibility with any strap. You can verify it by positioning a digital caliper on the inner shoulders of the lugs: the result will be 18.00 mm ±0.1 mm. All straps sized for 18mm will fit with precision without lateral play.

Medium-quality alligator in cognac or natural beige tones represents the noblest choice, as the irregular grain of the reptile naturally complements the golden texture of the case. Alternatively, vegetable-tanned calf leather with natural patina (dark brown or terracotta) creates an organic relationship with the gold over time. For pure elegance, bourbon shell cordovan expresses an unparalleled tactile density. For daily use, deep black calf leather maintains versatility and discretion.

The replacement is a simple operation: remove the lug pins using a spring bar tool (small instrument with a bifurcated tip), available at any jeweler or watch shop. Insert the bifurcated end under the internal spring of the pin until the spring compresses, then extract the pin while maintaining lateral traction toward the opposite side. Repeat for both lugs, then insert the new pins into the strap by engaging the locking mechanism at both lugs of the case. If you are not familiar with this procedure, consulting a professional watchmaker is the safest choice.

Yes, provided the lug width is exactly 18 millimeters. Any 18mm strap, regardless of brand, will mechanically fit the lugs of your Seamaster. However, construction quality and material nobility vary considerably: choosing first-rate leathers, millimetric stitching, and reliable <a href="/pages/termine-glossario/deployante">deployante</a> clasps ensures a transformation that does not compromise your solid gold investment.

A high-quality leather strap (alligator, shell cordovan, noble calf) maintains structural integrity for 3-5 years of daily use, depending on sun exposure, water, and temperature. Vegetable tanning develops natural patina over time, transforming aesthetically while maintaining mechanical resistance. Body perspiration and humidity accelerate aging: users wearing the strap in humid or hot environments will see reduced lifespan. Periodic maintenance (cleaning, conditioning) and occasional rest significantly extend durability. Casati Milano warranty is 18 months on made-to-measure straps, covering manufacturing defects.